I don't want 100 different SharePoint sites. How to create private teams w/o a new site?

You’re not crazy, and you’re not “doing SharePoint wrong”. What you’ve run into is the intentional design of modern SharePoint + Teams, colliding with how humans intuitively expect structure to work.

The hard truth (why this keeps happening)

Modern SharePoint uses a flat site architecture. Every SharePoint “site” you see in the admin center is a top‑level site collection, not a subsite or page. Microsoft intentionally killed hierarchical subsites because they caused massive problems with permissions, governance, and migrations. This is documented and by design.

From that single decision flows everything else:

• Creating a Team creates:
  • a Microsoft 365 Group
  • a new SharePoint site collection for files
• A standard channel = folder in that site
• A private or shared channel = another SharePoint site, because Microsoft enforces one rule:

Any security boundary == its own SharePoint site

This isn’t accidental, and there is no supported way to have true privacy in Teams without creating another SharePoint site. Microsoft is very explicit about this in their documentation. Private channels should be used sparingly for this exact reason.

Why Hub Sites exist (and what they actually are)

A Hub Site is not a parent site.

It does not contain other sites. It does not control permissions. It does not create hierarchy.

A hub site is a navigation, branding, search, and content aggregation layer that connects independent site collections into something users experience as a single logical space.

Hubs exist because SharePoint is flat. They are the modern replacement for the illusion of structure that subsites used to provide.

A structure that actually works (and is explainable)

If your goal is:

• minimal site sprawl
• human‑understandable structure
• privacy without chaos

Then this is the least bad model that consistently works in real organizations:

1. One Communication Site = the “company front door”

• Intranet / org home
• Policies, announcements, reference content
• No Teams, no projects, no collaboration
• Declare this site as a Hub Site

This gives you org‑wide navigation, branding, and search across everything associated with it.

2. Limit Teams to real, long‑lived teams

• Departments
• Stable product teams
• Long‑running programs

Not:

• Short projects
• “Phase 2 – Test – Copy”
• Temporary initiatives

Every Team creates a SharePoint site — so Teams creation must be governed, even if lightly.

3. Avoid private channels unless legally required

Private (and shared) channels will always create new SharePoint sites. There is no workaround.

If what you need is:

• management-only folders
• sensitive documents
• limited visibility

Use instead:

• separate document libraries
• broken permission inheritance
• or a standalone SharePoint site not connected to Teams

Yes, breaking inheritance is ugly — but it is visible, auditable, and does not create invisible sites that confuse everyone.

Microsoft themselves caution against overusing private channels for exactly this reason.

The mental model that actually clicks

This is how it finally makes sense to technical people:

SharePoint sites are not “websites”.
They are security and lifecycle containers that happen to have web pages.

Once you accept that, the rest becomes survivable.

Final reality check

You cannot have:

• one SharePoint site
• true security isolation
• Teams-style collaboration
• and zero additional sites

at the same time.

Hub Sites are Microsoft’s answer to this trade‑off: accept many sites, but present them as a single, coherent experience.

It’s not elegant. But with governance and restraint, it is understandable — and that’s the real optimization target.